<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        const canvas = document.createElement('canvas')
        canvas.width = 600
        canvas.height = 600
        document.body.appendChild(canvas)
        
        const ctx = canvas.getContext('2d')
        ctx.beginPath()
        ctx.translate(200,200) // 移动原点
        ctx.arc(0,0,100,0,Math.PI*2)
        ctx.moveTo(90,0)
        ctx.arc(0,0,90,0,Math.PI*2)
        ctx.strokeStyle = 'red'

        ctx.rotate(Math.PI) // 旋转

        ctx.moveTo(0,0)
        ctx.lineTo(-60,0)

        ctx.moveTo(0,0)
        ctx.lineTo(0,-80)

        ctx.stroke()
        


        
         
    </script>
</body>
</html>